public class Test1 {
    public static void main(String[] args) {
     MyStack myStack = new MyStack();
     myStack.push(1);
        myStack.push(2);
        myStack.push(3);
        myStack.push(4);

        System.out.println(myStack.peek());
        System.out.println(myStack.peek());
        System.out.println(myStack.peek());

    }
}
